The Patent Specification DK 176690 B1 discloses a suspension system, in particular for heavy work vehicles, which comprises a rigid front axle suspended from parallel, pivotable rods and from a triangular rod connection. The suspension system is capable of absorbing most of the occurring impacts from the wheels, so that these impacts are only transferred to the vehicle to a minor degree.
One of the drawbacks of this structure is that the system contains many movable parts and bearings which are subjected to wear, and that the free mobility of the system is limited by the mounting principle and the patterns of movement of the rod connections.
The document EP 0 932 512 B1 discloses a pendular spring mounted axle suspension where the relative movement of the axle and the chassis is limited by a pair of mechanical stops, which protrude vertically from the upper side of the axle on both sides and another pair of mechanical stops, pointing downwards from the chassis. The maximum angle between the axle and the chassis is limited to 11 degrees.